This research analyses the effect of Europeanisation on sovereignty in the post-Yugoslav states by examining the evolution of the different states’ policies related to extradition of their own nationals. Extradition is an important aspect of these countries’ political transformation, because the rule of law and regional co-operation are enshrined in the set of conditions these countries have to meet to enter the European Union. The research thus looks at how the different post-Yugoslav states approach the extradition of their own nationals, and whether they have altered them in view of the requirements of the accession process. By doing so, this paper looks at the dynamics between the duty of the state to protect its citizens and the transformative power of Europeanisation in the Western Balkans.